13.42 内尿系统
Section outline
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How is it determined what's waste and what's not?
::它如何决定什么是浪费,什么不是浪费?Getting rid of waste and excess is a major process of maintaining . Such a basic process is actually very complex. It involves an intricate exchange of material through the .
::清除浪费和过剩是维持这个过程的一个重要过程。 这种基本过程实际上非常复杂。 它需要通过这个过程进行复杂的材料交换。Urinary System
::内脏系统The kidneys are part of the urinary system , which is shown in Figure . The main function of the urinary system is to filter waste products and excess water from the and excrete them from the body.
::肾脏是尿道系统的一部分,如图所示。 尿道系统的主要功能是过滤废物和多余的水,从身体中排出。The kidneys are the chief organs of the urinary system.
::肾脏是尿道系统的主器官Kidneys and Nephrons
::肾和肾The kidneys are a pair of bean-shaped organs just above the waist. A cross-section of a kidney is shown in Figure . The function of the kidney is to filter blood and form urine . Urine is the liquid waste product of the body that is excreted by the urinary system. Nephrons are the structural and functional units of the kidneys. A single kidney may have more than a million nephrons!
::肾脏是腰部上方的一对豆形器官。图中显示了肾的交叉剖面。肾的功能是过滤血液和形成尿液。尿液是被尿道系统排出的身体的液体废物。内弗龙是肾的结构和功能单位。单肾可能有超过100万个肾脏!Each kidney is supplied by a renal artery and renal vein.
::每个肾脏都有肾动脉和肾静脉As shown in Figure , each nephron acts as a tiny filtering plant. It filters blood and forms urine in the following steps:
::如图所示,每颗甲状腺都起到小过滤装置的作用,过滤血液和尿液,其步骤如下:-
Blood enters the kidney through the
renal artery
, which branches into capillaries. When blood passes through capillaries of the
glomerulus
of a nephron,
forces some of the water and dissolved substances in the blood to cross the capillary walls into
Bowman’s capsule
.
::血液通过肾动脉进入肾脏,而肾动脉的分泌则通过刺膜。 当血液通过肾脏球状体的毛细膜时,迫使一些水和血液中的溶解物质穿过毛细墙进入鲍曼的胶囊。 -
The filtered substances pass to the
renal tubule
of the nephron. In the renal tubule, some of the filtered substances are reabsorbed and returned to the bloodstream. Other substances are secreted into the fluid.
::过滤物质传递到肾脏管,在肾管管中,有些过滤物质被重新吸收并返回血液中,其他物质被隐藏在液体中。 -
The fluid passes to a collecting duct, which reabsorbs some of the water and returns it to the bloodstream. The fluid that remains in the collecting duct is urine.
::液分流到一个收集管,再吸收一些水,再返回到血液中,收集管中残留的液是尿。
The parts of a nephron and their functions are shown in this diagram.
::该图显示了一个肾的部位及其功能。Excretion of Urine
::尿液排出From the collecting ducts of the kidneys, urine enters the ureters , two muscular tubes that move the urine by peristalsis to the bladder (see Figure ). The bladder is a hollow, sac-like organ that stores urine. When the bladder is about half full, it sends a to a sphincter to relax and let urine flow out of the bladder and into the urethra . The urethra is a muscular tube that carries urine out of the body. Urine leaves the body through another sphincter in the process of urination . This sphincter and the process of urination are normally under conscious control.
::尿液从肾脏的收集管道进入尿管,两个肌肉管将尿液穿透到膀胱(见图 ) 膀胱是一种空洞的、类似于囊状的器官,可以储存尿液。当膀胱大约满半时,它会将一个螺旋体送到一个螺旋体,让尿液从膀胱和尿道中流出,让尿液从尿道中流出进入尿道。尿道是一种肌肉管,可以将尿液从身体中流出。尿液在尿道中通过另一个螺旋体离开身体。这种螺旋体和尿道通常在有意识的控制之下。Summary
::摘要-
The kidneys filter blood and form urine. They are part of the urinary system, which also includes the ureters, bladder, and urethra.
::肾脏过滤血液和尿液,是尿道系统的一部分,也包括尿管、膀胱和尿道。 -
Each kidney has more than a million nephrons, which are the structural and functional units of the kidney.
::每个肾各有100多万个肾,它们是肾的结构和功能单位。 -
Each nephron is like a tiny filtering plant.
::每颗肾像一个微小的过滤工厂
Review
::回顾-
Describe how nephrons filter blood and form urine.
::描述甲状腺如何过滤血液和形成尿液。 -
State the functions of the ureters, bladder, and urethra.
::尿管、膀胱和尿道的功能
-
Blood enters the kidney through the
renal artery
, which branches into capillaries. When blood passes through capillaries of the
glomerulus
of a nephron,
forces some of the water and dissolved substances in the blood to cross the capillary walls into
Bowman’s capsule
.
